No noto yo-yo

I am sorry that John Sparks (THES, July 10), who is so much on the same side as I am when it comes to teaching in higher education, thinks it necessary to take me to task, but his "trial and error" is not the same as my "refining over time".

Of course lecturers should have a better understanding of how teaching and learning are related than they normally have at present. This relationship, however, is far too complicated to always get it right first time.

"Requiring students to put up with their teachers' failings" is surely a caricature of "improving in the light of evaluated practice". However, I should perhaps have resisted the temptation of the soundbite "doing the right thing wronger before doing it righter".

And was the Plowden report so wrong that rather than improvement through constructive evaluation it is thought necessary to go back to the methods that did not work before Plowden?

The yo-yo is not a good model for educational change.

Lewis Elton Professor of higher education University College, London